The time period of a simple pendulum is T. When the length is increased by 10 cm, the period is T1.When the length is decreased by 10 cm, its periodis T2. Then relation between T, T1, T2 is
T1=2r√l+10cmg;T2=2π√l−10cmg
T12+T22=4π2(2l+10cm−10cmg)
T12+T22=2T2